Integrated circuits (ICs) and other electronic devices are commonly packaged in so-called IC chip carriers. A chip carrier comprises a body of insulating material having the IC chip contained therein and having contact pads at predetermined space locations near its periphery. The dimensions and other standards for such chip carriers are established in a specification, commonly referred to as the JEDEC standard which was established and which is maintained by the Electronics Industries Association of 2001 I Street, N.W., Washington D.C., 20006.
Connectors for integrated circuit chip carriers, such as chip carrier sockets or other types of connectors, must be manufactured so that the contact members in the connector housing will contact the pads in the integrated circuit chip carrier when the chip carrier is assembled to the connector housing. The connector thus must have some sort of a positioning means for locating the chip carrier on the connector, one such positioning means being shown in U.S. Application Ser. No. 818,831 filed Jan. 14, 1986 and comprising keys and keyways in the connector housing and in the chip carrier. Another known method of locating the chip carrier on the connector housing is to provide notches on three corners of the square chip carrier body, a beveled corner on the body, three locating pins on the connector housing, and a biasing spring on the housing.
Standard chip carriers are produced with varying numbers of contact pads or "postions" ranging from 64 positions to 164 positions or even more in proposed new designs. It can thus be appreciated that as the number of positions on the chip carrier increases, the difficulties in manufacturing the connector increase. The manufacturing difficulties encountered stem largely from the requirement that the contact members in the connector must all engage the contact pads in the chip carrier and when there are a high number of contact pads and therefore contact members in the connector, cumulative tolerance buildup problems become increasingly difficult to solve.
It is known to produce connectors for IC chip carriers in the form of a housing having a plurality of contact modules therein or thereon, each contact module comprising usually a length of insulating material having spaced-apart metallic contact terminals or other contact devices therein, see for example U.S. Pat. Nos. 3,960,423, 4,571,015, and 4,593,463. The use of contact modules offers several advantages such as the fact that different types of modules can be fitted into a standard housing frame so that a single type of frame can be used for an entire family of connectors such as chip carrier sockets. Additionally, the use of modules frequently will simplfy the manufacturing process.
The manufacturing problems discussed above regarding cumulative tolerances in IC chip carrier connectors have heretofore discouraged the use of the module approach to connector manufacturing, particularly for the higher count chip carrier connectors such as those designed to accept chip carriers having 164 contact pads thereon. The difficulty of positioning the module on the connector housing with sufficient precision to enable the contact members in the module to engage the contact pads or positions on the chip carrier itself have largely been the cause of the limited use made of this modular approach in the past.
The present invention is directed to the achievement of an improved connector for an IC chip carrier or other substrate which contains a plurality of contact modules mounted in a frame and which has positioning means for the modules which permit the connector to accept chip carriers having relatively high numbers of contact positions thereon. The connector may be a conventional chip carrier socket or it may be of other types as will be described below.